For a city with such outstanding seafood credentials, it’s ironic that one of San Francisco’s best-known foods is a sourdough bread bowl filled with gloppy clam chowder. The dish—a symbol of handy ingenuity for tourists, an object for contempt for locals—has been a Bay Area mainstay since it gained traction around Fisherman’s Wharf in the early 1990s.

The ISIS terrorist organization is threatening to launch new attacks in San Francisco, New York, and London, according to new warning messages posted on the group’s social media channels. The messages, carried across the internet via the Telegram networking website, feature the three cities and call for adherents of the terror group’s radical ideology to “kill them all,” according to copies of the warnings obtained by the Middle East Media Research Institute, or MEMRI, a group that monitors jihadi networks.